This invention generally relates to apparatus and method for forming an absorbent web. In particular configurations, the apparatus and method can substantially continuously deliver an absorbent web having side edges that have been shaped with a contour pattern that is asymmetric along a lengthwise dimension of the shaped web. The shaped, absorbent web can be employed to produce an absorbent pad for applications such as disposable diapers, child""s training pants, feminine care articles, incontinence articles, and the like.
In the general practice of forming absorbent web materials, the webs have been formed by employing conventional airlaying techniques. For example, it has been common to utilize a fibrous sheet of cellulosic or other suitable absorbent material which has been fiberized in a conventional fiberizer, or other shredding or comminuting device, to form discrete fibers. In addition, particles of superabsorbent material have been mixed with the discrete fibers. The fibers and superabsorbent particles have then been entrained in an air stream and directed to a foraminous forming surface upon which the fibers and superabsorbent particles have been deposited to form an absorbent fibrous web. The absorbent web can then be directed for further processing and assembly with other components to produce a final absorbent article.
In other ordinary techniques, preformed absorbent sheets or layers have been delivered into a manufacturing line from an operative preformed supply, such as provided by a supply roll. The preformed absorbent sheets have been composed of absorbent fibers, synthetic fibers and superabsorbent materials in desired combinations. In particular, manufacturing processes, the preformed absorbent sheets have been separated into adjacent strips having various configurations of xe2x80x9cnestedxe2x80x9d shapes. The preformed absorbent materials can be expensive, and the nested shapes have been employed to reduce any wastage of the preformed sheet material. The strips of absorbent material may then be assembled together in various ways and combined with other components to generate a desired absorbent article.
Conventional techniques, such as those described above, have continued to exhibit various shortcomings when employed to form absorbent structures from preformed layers of absorbent material. For example, with the conventional techniques, it has been difficult to fully utilize the adjacent, shaped strips of nested absorbent material when the nested-shapes of the absorbent strips have a contoured repeat-pattern that is non-symmetric with respect to longitudinal, lengthwise dimension of the strips. Where the repeat-pattern is longitudinally asymmetric, a single cycle of the repeat-pattern of one shaped-strip can be longitudinally reversed, as compared to a single cycle of the repeat-pattern of an immediately adjacent shaped-strip. As a result, it has been difficult to efficiently use the immediately adjacent, shaped-strips on a single manufacturing line. For example, it has been difficult to serially connect the immediately adjacent, shaped-strips, and use the connected strips on a manufacturing line having a pre-established sequence of assembly operations. It has also been difficult to superpose portions of immediately adjacent, shaped-strips during an inline process because the adjacent strips have non-matching shapes. Accordingly, it would be a substantial advance in the art to provide a method and apparatus which can provide a more efficient handling and use of adjacent, nested strips which have been separated from a supply sheet, wherein the separated edges represent a repeat-pattern having a pattern shape that is non-symmetric with respect to the lengthwise dimension of the strips.
A method and apparatus for making an absorbent article can include a delivering of a first contoured web-strip from a first production supply of contoured web-strip material, with the first contoured web-strip presenting a primary production sequence of side edge contours during its delivery. At least a second contoured web-strip can be delivered from a second production supply of the contoured web-strip material, with the second contoured web-strip presenting the primary production sequence of side edge contours during its delivery. In a particular feature, the first and second contoured web-strips have been produced from a web of absorbent material which has been divided to provide at least two web-strips having a substantially nested configuration. In another feature, the first web-strip can provide a first orientation which presents a first sequence of side edge contours; and the second web-strip can provide a longitudinally-reversed orientation which presents a different, substantially reversed sequence of side edge contours. In an additional feature, the web-strips have been separately stored to provide the first and second production supplies of contoured web-strip material.
By incorporating the various aspects and features into desired configurations, the present invention can more efficiently use the immediately adjacent, shaped-strips that have been formed in a nested configuration with a repeat-pattern shape that is longitudinally asymmetric. For example, the invention can more efficiently connect the immediately adjacent, shaped-strips in series, and use the connected strips on a manufacturing line having a pre-established sequence of assembly operations. The invention can also more efficiently superpose selected portions of immediately adjacent, shaped-strips onto each other during an inline process because the adjacent strips have substantially matching shapes. Accordingly, the technique of the present invention can provide a more efficient handling and use of adjacent, nested strips when the nested strips have been separated from a supply web in a manner which provides a contoured repeat-pattern having a single-cycle pattern shape that is non-symmetric with respect to the lengthwise dimension of the strips.